Improvement in pipe-tongs



J. D. DAVIS. Pipe-Tongs.

Patented July 15,1879

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N. FErERS, PHOTO-LITHOGHAPHER. WASHINGTON. D C

UNITED STATES PATENT OFFIoE.

JONATHAN D. DAVIS, OF FITCHBURG, MASSACHUSETTS, ASSIGNCR TO CHARLES PUTNAM, OF SAME PLACE.

IMPROVEMENT IN Pl PE-TONGS.

Specification forming part of Letters Patent No. 217,450, dated July 15, 1879; application filed December 12, 1878.

To all whom it mag concern:

Be it known that I, JONATHAN D. DAVIS, of Fitchburg, in the State of Massachusetts, have invented a new and Improved Pipelongs; and hereby declare the following to be a full, clear, and exact description of thereof, reference being had to the accompanying drawings, making part of this specification, in which- Figure 1 is a perspective view of the tongs with the jaws open. Fig. 2 is a section of the same. Figs. 3 and 4 are details to be referred to.

My invention relates to that class of pipetongs wherein one leg has a slot in it for a movable bearing, to which is attached the other leg, so that the distance between the jaws may be increased or diminished at will and it consists in a movable rotating internally-threaded bushing located in the slotted leg, and into which telescopes the screw controlling the movable bearing for the movable aw.

In order that those skilled in the art may make and use my invention, I will proceedto describe the manner in which I have carried it out.

In the said drawings, A is the movable leg .of the tongs, and B the slotted leg, provided with the slot 1) and bearing cfor the adjusting devices. Inside of the bearing cis acylinder, d, having a shoulder, e, or other means for taking up the longitudinal thrust on said cylinder when crowded upward against the shoulder z in the end of the bearing. At its lower end bearing 0 is provided with a shoulder, 6, against which abuts a shoulder, a, on cylinder d. Internally this cylinder is threaded to receive the screw 8, which is attached to and controls the movable bearing D, holding the pivot d, on which the jaws turn, and the movement of said pivot controlling the dis;-v

tance between the jaws.

Fig. 2 illustrates that cylinder d! can be freely revolved in its bearing by means of a thumb-screw piece, t, and the screw 8, run back. and forward in and out of the cylinder.

Figs. 4 and 5 show two forms of bearing, one separated from the adjusting-screw, and one made in a single piece with it.

The device for the jaw-bearing shown in Fig. 4 operates positively by the motion of the screw and changes the jaws.

The device shown in Fig. 5 does not positively change the position of the jaws, and the change has to be effected when the screw 8 is Withdrawn.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

In an adjustable pipe-tongs, the bearing 0, provided with the shoulders 45 i, in combination with the internal telescopic threaded sleeve (1, provided with shoulders e e, screw 8, pivot d, and jaws A B, said jaw B being provided with a slot, 1), as set forth.

* JONATHAN D. DAVIS.

Witnesses:

S. W. PUTNAM, GEo. A. 'WrnsoN. 

